Indeed, it’s important to remember that alongside the construction of the Metaverse, a complementary and equally ambitious infrastructure project is under way. It’s the wiring of the entire world, without the wires: tiny ­radio-­connected sensor chips are being attached to everything worth moni­toring, including bridges, ventilation systems, light fixtures, mousetraps, shipping pallets, battlefield equipment, even the human body. To be of any use, the vast amounts of data these sensors generate must be organized and displayed in forms that diagnosticians or decision makers can understand; “reality mining” is the term researchers from Accenture Technology Labs, the MIT Media Lab, and other organizations are using for this emerging specialty. And what better place to mine reality than in virtual space, where getting underneath, around, and inside data-rich representations of real-world objects is effortless?

In the field, technicians or soldiers may get 2-D slices of the most critical information through wireless handheld devices or heads-up displays; in operations centers, managers or military commanders will dive into full 3-D sensoriums to visualize their domains. “Augmented reality and sensor nets will blend right into virtual worlds,” predicts ­Linden Lab’s Ondrejka. “That’s when the line between the real world and its virtual representations will start blurring.”

I asked David Gelernter why we’d need the Metaverse or even mirror worlds, with all the added complications of navigating in three dimensions, when the time-tested format of the flat page has brought us so far on the Web. “That’s exactly like asking why we need Web browsers when we already have Gopher, or why we need Fortran when assembly language works perfectly well,” he replied.

Once you've downloaded the appropriate software from Second Life and Google Earth, many locations mentioned in this story can be accessed using special links in the copy. Links saying "SLurl" will open a Second Life viewer. Links saying "Google Earth location" will open Google Earth and spin the virtual globe to the proper coordinates.

The current Web might be capable of presenting all the real-time spatial data expected to flow into the Metaverse, Gelernter elaborates, but it wouldn’t be pretty. And it would keep us locked into a painfully mixed and inaccurate meta­phor for our information environment–with “pages” that we “mark up” and collect into “sites” that we “go to” by means of a “locator” (the L in URL)–when a much more natural one is available. “The perception of the Web as geography is meaningless–it’s a random graph,” Gelernter says. “But I know my physical surroundings. I have a general feel for the world. This is what humans are built for, and this is the way they will want to deal with their computers.”

Judging by the growing market for location-aware technologies like GPS cell phones, the popularity of map-based storytelling and neogeography mashups like Platial, and the blistering pace of Google Earth downloads, Gelernter may be right. Google Earth is now so well known that it has been satirized on The Simpsons and is becoming a forum for classified ads and résumés. Second Life, meanwhile, is gaining roughly 25,000 members a day, sometimes stretching Linden Lab’s ability to keep its simulations running smoothly.

But for a true Metaverse to emerge, programmers must begin to weave together the technologies of social virtual worlds and mirror worlds. That would be a simpler task if Google and Linden Labs would release the source code behind their respective platforms, or at least provide application programming interfaces (APIs) so that outside developers could tap into their deeper functions. In late 2006, Google released an interface that allowed outside programmers to control some aspects of Google Earth’s behavior, but it wasn’t a full API, and there’s been no sign of one since. This January, Linden Lab released the source code for the Second Life viewer (the program that residents use on their PCs to connect to Second Life). Ondrejka says the code for the core Second Life simulation software will follow. First, he says, the company needs to get that software working better–and figure out how to make money in a world where it may no longer control the expansion of the Second Life ecosystem.

The real progress toward a fusion of Second Life and Google Earth is going on outside their home companies. Last year, Andrew “Roo” Reynolds, a “Metaverse evangelist” at IBM’s Hursley laboratory in England, hacked together an extension for SketchUp that turns Collada 3-D models into prim-based objects in Second Life. And while it may be impractical to make Second Life into a walkable Google Earth, Daden, a company in Birmingham, England, is bringing Google Earth into Second Life. The result isn’t exactly a globe, however. It’s a virtual virtual-reality chamber where the Google Earth continents are displayed as if pasted to the inside of a giant sphere, with the user’s avatar at the center. Clickable “hot spots” bring up real-time earthquake data and news feeds from CNN, the BBC, and the Indian Times [video] [SLurl; read the sign and click the button marked “TP”].